The first thing to be said about today's royal wedding is unconditional. We wish Prince William and Catherine Middleton a long and happy married life together. From that wish, a range of other simple and unvarnished hopes – which strangers with goodwill towards any marriage instinctively feel – all follow. That the day goes well for the couple in every possible way. That today's pageantry is not marred by anything inappropriate. That the young couple's happiness is the day's focus and its abiding memory. That, from today, William and Catherine are now allowed some privacy as they accustom themselves to the private and public changes that their wedding heralds. We hope that today's marriage – and you may choose whatever meaning you are most comfortable with from this wish – will be truly blessed.

We also hope, in spite of this paper's continuing republican sympathies, that today's wedding can be a useful collective experience for the Britain over which today's couple may reign one day as King and Queen. After the hysteria, infantilisation and general disproportion that so often surrounded royal events towards the end of the 20th century, a proper sense of perspective about where this wedding stands in the national scheme of things in the 21st would be very welcome and reassuring.

Benevolent mood

In the past days and weeks, the public has shown rather more sign of possessing that good judgment than much of the media has done. This is not a fairytale moment. Modern Britain is not fairyland. A Guardian/ICM opinion poll earlier this week found only one in five Britons admits to being strongly interested in today's events. Three out of four, on the other hand, recognise that today should help to cheer the nation up a bit. The mood, in other words, is rightly benevolent, though as much for a welcome day off, and perhaps a bit of a party, as for any great constitutional issue. It is not entirely clear whether Buckingham Palace gets it. It would definitely have helped, in this low-key but big-tent spirit, if the royals had invited former Labour prime ministers as well as inviting former Conservative ones. That spiteful symbolic snub, alongside the tickets dished out – and in Syria's case withdrawn – to tyrants and their professional apologists, speaks volumes about a British ruling class which is slipping quickly back into its old ways now that the natural order of things has been restored under the Tories.

The future of the monarchy, though, is very clearly a matter for another day rather than this. When that debate comes, which it should and will – certainly before the next reign – the outcome will depend on events and personalities as much as on constitutional principle. The removal of the indefensible parts of the Act of Settlement is an early priority, and now has David Cameron's backing. Last weekend's poll depicted us as a people made up of a large majority of moderate rather than hysterical monarchists and a significant minority of not implacable republicans. But these sentiments are not set in stone. The monarchy's place in the British people's sense of patriotism is contingent. In a democracy, nothing should be taken for granted. Prince William and Ms Middleton, whose generation is less monarchist, seem more alive to this mood than the generation of Princes Charles and Andrew.

Recent royal history makes the cautious approach unavoidable. For all the understandable excitement associated with a very public wedding and national occasion, there is an equally understandable public soberness this time too. These are tough times for millions of British people. This is not a day for demented princess worship or for in-your-face state extravagance. Even if it was, the recent past inevitably casts a shadow over the occasion. As far as dream royal weddings are concerned, Britain is a once-bitten-twice-shy country.

Those who remember the wedding of Prince Charles and Lady Diana Spencer, 30 summers ago, will sense the welcome difference of tone this time. The wedding of 1981 was fuelled by excitement and generosity too. But it was also pumped up with an overdose of public adrenaline, much of it media-driven. This helped to create an unrealistically heavy expectation whose weight even a much better matched couple than Charles and Diana would have struggled to bear. Theirs was the supposedly fairytale wedding that became a wretched marriage with a tragic outcome. Human beings do not always learn from their mistakes. But the build-up to the wedding of 2011 has been a bit more restrained. And that provides cause for hope that some of the public foolishness and private misery of last time will not be repeated.

Back to reality

So, have a wonderful day. But stay real about it too. Any wedding is a statement of hope about the future; the grandest and most public wedding of this generation inevitably makes a bigger statement. But how big should that statement be? That the marriage of a prince and his bride somehow make everything better and more meaningful for the rest of the nation? That would be a profoundly false message. Away from the pealing bells and swelling choruses in the abbey, today's grandeur is largely vicarious. Hope is a commodity in short supply right now, even – and in many cases especially – among William and Catherine's fellow twentysomethings. In any generation there is room for only one king and one queen. Millions of the young couple's fellow citizens in their 20s, meanwhile, lead lives marked by student debt, by the difficulty of finding a secure job, of getting somewhere affordable to live, and of matching their lived reality to the material and emotional aspirations the surrounding culture sleeplessly and cruelly promotes to them. Not all of their relationships endure either.

Enjoy the big show. Good luck to the newlyweds. But the public mood is right. For most of us this is a day off. It is a day for a smile and a toast, not a day for standing to attention and tugging of forelocks. Tomorrow, and on every other day of the year, we will have to re-enter the world of reality.